<s>
Back	B-Language
In	I-Language
Time	I-Language
is	O
a	O
backup	B-Application
application	O
for	O
Linux	B-Application
.	O
</s>
<s>
It	O
has	O
versions	O
that	O
integrate	O
favorably	O
in	O
GNOME	B-Application
and	O
KDE	B-Language
SC	I-Language
4	I-Language
and	O
is	O
available	O
directly	O
from	O
the	O
repositories	B-Application
of	O
many	O
Linux	B-Application
distributions	I-Application
.	O
</s>
<s>
Released	O
under	O
the	O
terms	O
of	O
the	O
GNU	B-License
General	I-License
Public	I-License
License	I-License
(	O
GPL	B-License
)	O
,	O
it	O
is	O
free	B-Application
software	I-Application
.	O
</s>
<s>
Back	B-Language
In	I-Language
Time	I-Language
uses	O
rsync	B-Application
as	O
backend	O
and	O
has	O
the	O
characteristic	O
feature	O
of	O
using	O
hard	B-Application
links	I-Application
for	O
files	O
which	O
are	O
identical	O
in	O
snapshots	O
at	O
different	O
times	O
,	O
thus	O
using	O
disk	O
space	O
just	O
once	O
for	O
files	O
that	O
remained	O
unchanged	O
.	O
</s>
<s>
It	O
is	O
possible	O
to	O
use	O
several	O
backup	B-Application
profiles	O
,	O
e.g.	O
</s>
<s>
for	O
backups	B-Application
on	O
different	O
hard	O
disks	O
and	O
also	O
to	O
create	O
schedules	O
.	O
</s>
<s>
Symbolic	B-Application
links	I-Application
can	O
be	O
backed	O
up	O
,	O
both	O
absolute	O
and	O
relative	O
ones	O
,	O
but	O
hard	B-Application
links	I-Application
cannot	O
be	O
treated	O
as	O
such	O
due	O
to	O
the	O
used	O
backup	B-Application
method	O
.	O
</s>
<s>
Back	B-Language
In	I-Language
Time	I-Language
also	O
supports	O
encryption	O
of	O
backups	B-Application
and	O
backup	B-Application
over	O
SSH	B-Protocol
.	O
</s>
<s>
Advantages	O
of	O
the	O
hard	B-Application
link	I-Application
method	O
are	O
that	O
it	O
is	O
easy	O
to	O
look	O
at	O
snapshots	O
of	O
the	O
system	O
at	O
different	O
times	O
and	O
also	O
easy	O
to	O
remove	O
old	O
snapshots	O
compared	O
to	O
incremental	O
backup	B-Application
methods	O
which	O
save	O
difference	O
information	O
between	O
consecutive	O
backup	B-Application
times	O
.	O
</s>
<s>
However	O
,	O
a	O
drawback	O
of	O
Back	B-Language
In	I-Language
Time	I-Language
is	O
that	O
it	O
does	O
not	O
allow	O
for	O
compression	O
,	O
and	O
requires	O
file	O
systems	O
that	O
support	O
hard	B-Application
links	I-Application
on	O
the	O
backup	B-Application
location	O
.	O
</s>
<s>
There	O
is	O
a	O
graphical	O
interface	O
written	O
in	O
Qt	B-Language
.	O
</s>
